The mod works just fine for me. Where have you got the game from? Do you have any other mods installed?
Please be careful because you need to start a
NEW GAME, considering that you have another script & main.scm file. If that doesn't work, are you sure you installed it correctly?
- Back-Up your original main.scm & script files located at GTA San Andreas\data\script.
- After backed-up, replace the main.scm & scripts files with the new main.scm & script from the mod.
- Back-Up your original american.gxt located at GTA San Andreas\text folder.
- After backing-up that too, replace the american.gxt with the new one from the mod.
- Run the game, but remember to start a new game.
Good luck.